Embryonic stem cells capable of generating CNS glia can promote functional recovery after trauma to the spinal cord, and have potential for repair in demyelinating and dysmyelinating diseases such as multiple sclerosis. However, the use of embryonic stem cells for clinical therapy raises ethical concerns that cannot be easily addressed.
Somatic stem cells have also been proposed for therapeutic applications. For example, in animal models of cell replenishment therapy. The therapeutic potential of grafted stem cells can only be translated to clinical use if an ethically acceptable source of autologous stem cells is available, and if control of self renewal and fate decisions that program stem cell maturation into specific cell types is achieved.
Neurodegenerative disorders increasingly account for significant morbidity and mortality. Destruction of myelin underlies the most common neurological disorder in young adults, multiple sclerosis, and myelin affects repair after traumatic spinal cord injury, preventing regeneration of damaged neuronal axons and affecting electrical conduction in proximal, undamaged axons. Replacement of oligodendrocytes is thus a significant clinical goal. While oligodendrocytes are obtainable from neural stem cells, such stem cells are difficult to obtain.